Prime Minister Hun Sen yesterday blasted former Thai Prime Minister Abhisit Vejjajiva and Thai opposition activists for what he said were attempts to use Cambodia as a cudgel to score political points on sensitive issues back home.

Hun Sen was apparently reacting to a protest in Bangkok yesterday organised to oppose any International Court of Justice ruling on the Preah Vihear territory dispute, which is expected later this year.

Taking that as his launching pad, he said that Abhisit, whose Democratic Party shares political views with the protesters, had to “submit evidence” backing claims he’s made in the past about dealings between the two countries over a resource-rich overlapping claims area in the Gulf of Thailand.

“This former prime minister was always accusing former Thai Prime Minister Thaksin Shinawatra of benefiting from Cambodia over an oil and gas deal in the overlapping claims area, and opposing the ICJ’s jurisdiction,” Hun Sen said at in Stung Treng’s Siem Bok district where he distributed land titles.

“Today, I would like Abhisit to bring up evidence. But if there is no evidence, don’t rally to cheat more than 60 million Thai people, [as well as] 14 million Cambodian people.”

The first weeks of 2013 in Thailand have been marked by heated rhetoric over territory surrounding the Preah Vihear temple, which the ICJ awarded to Cambodia in a 1962 ruling. Hearings over the disputed area around the ruin are taking place this April at the court in The Hague. Like the temple, the overlapping claims area has been a source of tension between Cambodia and Thailand.

Developing the 26,000-kilometre area, believed to be rich in oil and gas, could mean new streams of revenue for both countries, and for companies holding concessions. A memorandum of understanding to jointly explore the area was first signed in 2001, but in more than 10 years, hopes for the agreement’s implementation have risen and fallen depending on who is in office in Thailand.

Those hopes went down along with former Thai Prime Minister Thaksin Shinawatra in 2006, when he was toppled in a military coup. It seemed to stay down three years later, after Hun Sen angered then-Thai Prime Minister Abhisit by appointing Thaksin as an economic adviser to the Kingdom.

But in 2011, in response to Abhisit reportedly accusing Thaksin of having “secret interests” in Cambodia, the Council of Ministers issued a statement that detailed closed-door meetings between Cambodian and Thai Democratic Party officials under Abhisit about the overlapping claims area.

The council’s Press and Quick Reaction Unit reissued its 2011 statement yesterday, and spokesman Phay Siphan said it was meant to be a reminder.

“The Thai people are [still] not aware that the Abhisit government tried to talk with Cambodia secretly about that issue. We want to put it on the table. That’s why we wanted to reveal the fact that Abhisit played with the people,” Siphan said.

Dialogue improved after the 2011 election of Thai Prime Minister Yingluck Shinawatra, Thaksin’s sister, but in recent months, no significant concrete steps have been announced.

To contact the reporter on this story: Vong Sokheng at [email protected]

Joe Freeman at [email protected]